Method of cleansing silver



' at Newark, in the county of Essex and State UNITED STATES PATENT OFFICE.

CHRISTOPHER J. THEUERNER, OF NEWARK, NEW JERSEY.

METHOD OF CLEANSING SILVER.

SPECIFICATION forming part of Letters Patent No. 490,816, dated January 31, 1893.

Application filed June 4,1892. Serial No. 435,549. (No specimens.)

To all whom it may concern.-

Be it known that I, CHRISTOPHER J. THEU- ERNER, a citizen of the United States, residing of New Jersey, have invented certain new and useful Improvements in Methods of Cleansing Silver; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The object of this invention is to secure a polish on articles of silver after the said articles have been subjected to the action of heat, to more quickly cleanse and perfectly remove the oxide especially in the small interstices or recesses in the ornamentation, and to prevent the sharp outlines of the said ornamentation being blunted or dulled by the bufling wheel.

The invention consists in the process or method of cleansing silver having a covering of oxide, substantially as will be hereinafter set forth and finally embodied in the clauses of the claim.

In carrying out the invention, in the course of manufacturing articles of silver for the market, the said silver having a coating of oxide or other compound, the result of the annealing operations, I subject the said silver to the action of an electrolytic bath, as an 1. The process or method of polishin g silver which consists in subjecting said silyer, as an anode, to an electrolytic bath containing cyanide of potassium, one part, and yellow prussiate of fitassium, two parts, substantially as set forth.

2. The process or method of polishing silver, which consists in subjecting silver coated with oxide to an electrolytic bath containing prussiate of potassium and cyanide of potassium, the oxide-coated silver being suspended as an anode of an electric circuit in said bath, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 20th day of May, 1892.

CHRISTOPHER J. TI'IEUERNER.

Witnesses:

CHARLES H. PELL, OSCAR A. MICHEL. 

